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What is stereo?

There are now two system of high fidelity, monophonic (monaural) and stereophonic. Monophonic is a system that starts from one microphone and is fed through a single high fidelity set. Stereophonic is a double system. Two separate microphones are placed at different sides of the orchestra and two different systems are used to keep the two signals or channels separated. Two separate speakers are used, placed on different sides of you room. Stereo is much like 3-D photography, two slightly different sound reach your ears giving you a new dimension in sound.

The
SL-1100AC provides that incomparable professional technics quality in a
reasonably priced package. The heart of this outstanding direct drive turntable
is its DC brushless motor which drives the platter directly to eliminate belts,
pulleys, and idlers. This simple design means fewer moving parts to wear out
and greater long term reliability. The motor is controlled electronically by a
DC servo which provides highly accurate rotation completely unaffected by power
line frequency and voltage variations.

And due to
its high torque, speed remains the same even during changes of external drag.
This combination produces wow & flutter of0,03% (WRMS) and rumble of better than -70 dB (DIN B).

The
turntable is dynamically balanced and of extra large size (35
cm/13-25/32") and weight (2 kg/4,4lb.) to contribute to overall high
performance.

The
tonearm is static balanced low mass tubular with a length (pivot to stylus) of 235 mm (9¼") for to tracking error. Effective arm
mass has been kept very low to accommodate high compliance cartridges. The headshell is made of precision diecast
aluminum with the universal type connector.

The SL-1600
features fully automatic play while incorporating the famous technics direct
drive motor and B.FG Servo One Chip IC
control System. The auto-mechanism
permits auto start, auto retur, and auto stop, and will automatically repeat a
record up to six times or indefinitely when the Memo-Repeat dial is set. A
simple flick of the auto start lever automatically lifts the arm from the rest,
places it on the record, returns it to the arm rest at the end of play, and
shuts off the turntable. Should you wish
to stop play in the middle of a record, simply slide the lever to the stop
position and the arm will automatically lift and return to the arm rest and the
power will ashut off. With this handy automatic feature, The SL-1600 brings you
the maximum in operating convenience with no compromise in turntable
performance.

The motor of
the SL-1600 is the incomparable Technics direct drive brushless DC motor which
contains only one moving part, the rotor, which is also the platter. For motor
drive and control this turntable employs our famous One Chip IC which is
equivalent to 321 separate electronic components.A B.FG (back-Electromotive-Force Frequency
Generator) servo control reglates the speed and issues instant correction
commands whenever necessary. The result; a spectacular wow & flutter
of0,025% (WRMS), an inaudibly low rumble of -73 dB (DIN B).

Rapid
atarting time,full speed within 1/3 rotation of a turn and 0% speed variation
up to 30 g tracking force. A number of measures are taken in the SL-1600 to
isolate the motor, platter and tonearm from outside vibrations. The Floating
Double Isolator insulates these important parts from most vibrations
transmitted through the floor or the air.

A heavy,
aluminum diecast base, a heavy zinc tonearm base, a newly designed turntable
mat, and precision made diecast aluminum cabinet also act to absorb vibrations
and keep them away from the record platter and the tonearm. And speaking of the
tonearm, it is gimbal suspended to ensure 7 mg friction. Effective arm mass has
been kept very low (22 g) to accomodate premium high compliance cartridges.
Other features include illuminated stroboscope, fine-scaled anti-skating
device, independent pitch controls variable by up to 10%, viscous-damped cueing
device and detachable dust cover.

The SL-1700
offers the famous Technics direct drive system with the added convenience of
semi-automatic operation. Once the tonearm is manually positioned over the
lead-in grooves, the automatic mechanism will lower the tonearm onto the record
when the lever is flicked, and automatically return it to the arm rest at the
complteion of play. The unit is then
automatically shut off. This handy feature frees the user from rushing to the
turntable at the end of record play and also saves wear on your stylus. At any time during play, flicking the stop
lever will cause the tonearm to automatically lift up and return to the arm
rest.

To control the DC direct drive motor, the
Sl-1700 incorporates a B.FG servo with One Chip IC which can perform the
functions of up to 321 transistors, diodes and resistors. B.FG stands for
Back-Electromotive-Force Frequency Generator and it desribes the method whereby
the back electromotive force induced by the rotor in the stator coils is used
to monitor the speed of the platter. The waveform obtained from this becomes
the reference for the frequency generator. Its output is compared with the
standard calibration frequency obtained from the reference oscillator and then,
when needed, a correction signal instantly changes the motor drive current to
the proper value to turn the platter at precisely the right speed. Wow &
flutter for the SL-1700 is an insignificant 0,025% (WRMS), while rumble is -73
dB (DIN B).

The SL-1700
also is equipped with Technics newly designed Floating Double Isolator, which
prevents acoustic feedback by shielding the turntable and tonearm assembly from
external vibrations. This isolator actually insulates the turntable from the
outside with two layers of specially designed isolators constructed of metal
springs and special vibration absorbing material.

The SL-1700
is equipped with several other defences against acoustic feedback; a heavy zinc
alloy tonearm base, a newly designed turntable mat, and a precision made
diecast aluminum cabinet. The tonearm is gimbal suspended to achieve 7 mg
friction. Effective arm mass has been kept very low (22 g) to accommodate
premium high compliance cartridges.

Other
features of the Sl-1700 include a fine-scale direct reading anti-skating
control, illuminated stroboscope, independent pitch controls variable by up to
10%, viscous-damped cueing device, and detachable dust cover.

The
SL-1800 features full Technics uncompromised direct drive performance in a
simple, straightforward package. The centre ofthis sleek,attractive unit is its
highly accurate One Chip IC controlled B.FG servo DC motor. This direct drive
motor, which incorporates all of the design features of all Technics fine dd
motors, is controlled by the unique B.FG (Back-Electromotive-Force Frequency
Generator) system which utilizes the back electromotive force induced by the
rotor in the stator field coils to monitor yhe platter speed. The frequency
generator uses the waveform obtained as its reference and it is compared with
the standard calibration frequency from the reference oscillator. In this way ,
a signal to correct the speed can be sent instantly whenever needed to change
the motor drive current in order to maintain precise platter speed.

This B.FG
principle greatly improves speed stability and gives a shorter build-up time.
It also maintains the platter speed under varying oad conditions. The above
mentioned control circuitry is all contained in a fantastic One Chip IC which
can perform the functions of up to 321 separate elements such as transistors,
diodes and resistors. The sum of all this electronic and mechanical advancement
is performance, the kind of super performance that produces the low wow and
flutter figure for SL-1800 of only 0,025% (WRMS), a figure almost unsurpassed
by any other turntable anywhere. Rumble is -73 dB (DIN B). Another outstanding
feature of the SL-1800 is the Floating Double Isolator. This new advance fights
against acoustic feedback by shielding the turntable and tonearm assembly from
all outside vibrations with two separate isolators constructerd of metal
springs and special vibration absorbing material.

The SL-2000
is designed for those who want direct drive performance at a moderate cost.
This beauty is equipped with Technics famous brushless DC motor, which operates
free from power line fluctuactions and trouble causing heat and hum. The
absence of moving parts in the motor means better reliability and longer
service life. Completely accurate platter speed is quaranteed by a One Chip IC
servo control, a simple and compact unit equivalent to 78 electronic
components. The result of all this precision is wow & flutter of only
0,045% (WRMS) and rumble 0f -70 dB (DIN B).

A precisely
manufactured tonearm ensures minimum tracking error and optimium mass
distribution for high compliance cartridges. Clear and clean sound reproduction
is assisted by the Insulation Fibre Board (IFB) and a newly developed insulator
which effectively shields the motor and tonearm assembly from outside
vibrations. The heavy zinc diecast tonearm base also works to prevent vibration
and subsonic resonances.

Other
features include a fine-scale (increments of 2,5g) direct reading antiskating
device, an illuminated stroboscope, independent pitch controls variable by up
to 10%, viscous-damped cueing, aluminum diecast universal headshell, and
detachable dust cover.

When
Technics first introduced the direct drive turntable back in 1969, we were sure
that our new drive design would revolutionize turntable manufacre. Subsequent
history has shown that we were correct. The direct drive system was so much of
an improvement oer the old way that it just couldn't be ignored, and the rest
of the audio world was quick to imitate us. Today the direct drive turntable
has become the industry standard, and it's no wonder. Just take a look at the
direct drive advantages.

Greater
Simplicity

In the
Technics integral rotor-platterstructure direct drive system, the platter
serves as the rotor and the motor housing serves as the stator. Thus, the
plater is the only moving part. No pulleys, no belts, and no idlers are needed
to drive the platter. Construction is greatly simplified and overall precision
is much greater. And with fewer parts to wear out, reliability and service life
is vastly improved.

Greater
Efficiency

The direct
drive motor runs at an ultra-slow speed since it need rotate no faster than the
platter. This reduces mechanical wear and stress, causes less evaporation. The
brushless DC motor has a power consumption 90% lower than conventional motors.
This means much less trouble causing heat and lengthened service life of all
parts. And the elimination of the Ac motor means the elimination of hum and
power line frequency variations as a source of speed inaccuracy.

Higher
Performance

The real
payoff is in performance. The simple construction of the direct drive system
enables much more precise construction and easier quality control. This has
permitted the reduction of wow and flutter to spectacularly low levels and the
total elimination of rumble as a source of interference. As you can, see it is
no exaggeration to say that the technics direct drive turntable has
revolutionized the world of turntables.

Double
Isolated Suspension System

As they
have done in so many oyher areas of turntable design, Technics engineers have
come up with an ingenious and unique method of coping with the acoustic
feedback problem; the floating double isolator. External sounds and vibrations
that reach the turntable either through the air or throught the unit's resting
position - are met by two separate isolation systems. The first isolators
effectively dampen harmful external vibrations which may reach the unit through
the surface that it rsts on. The all important turntable, motor and tonearm
assembly are then supported on a main base which floats on the secondary
isolation system. These isolators are specially designed with material and
springs of calculated and finely tuned elasticity to absorb external
vibrations. The result is an audible clearity and transparency in sound.

Gimbal
Suspension Tonearm

For the
finst tracing senstivity, Technics tonearms rest in a gimbal suspension
equipped with two pairs of low friction pivot bearings. With this enhanced
rotational sensitivity, the tonearm is allowed free, gyroscopic movement to
ensure flawless tracking.

One Chip
IC Control

Most
Technics direct drive turntables incorporate sophisticated one chip interated
circuits to govern all motor control funtions. This One Chip IC is one of teh
secrets behind the spectacular performance achieved by Technics DD unit. The
B.FG principle (Back-Electromotive-Force Frequency Generator) causes a near
instantaneous current change to correct for even the slightest speed deviation,
assuring highly stable rotation.

Quartz Phase-Locked Servo Control

The quartz oscillator, the most accurate method known for electronic frequency control, is used in Technics professional grade turntables to provide the basic reference frequency for all motor movements and for the stroboscope. This allows the achievement of the fantastically low speed drift figure of ±0,002%, or a maximum of ±0,036 second error over the 30 minute playing time of a typical LP side.

High
Starting and Running Torque

Due to exceptionally high motor torque (6 kg-cm), speed built-up is an
amazing 0,25 second. Normal operating speed (33⅓ rpm) is reached
after only a 25 degree turn of the platter.

The fine
quality of this integrated stereo amplifier has been achieved by the
application of some of the most advanced technology known in the audio field.
Total harmonic distortion, for example, is under 0,1% at full rated output. And
ezch channel delivers a full 25 watts throughout the audio spectrum - from 20
to 20,000 Hz at 8 ohms - for rich, clean sound. Dynamic music power reaches 100
watts but for those who love music, quality comes first, and for crystal-clear
room-filling beautiful sound, the KA-1500 has few rivals.

High
Powerand Low Distortion

Using fully
complementary circuitry that's direct-coupled throughout, the KA-1500 delivers
its power with a THD that is under 0,1% at all frequencies from 20-20,000 Hz.
The high quality of sound achieved is evident not only at first hearing but
also in the absence of "listening fatigue" after many hours of
enjoyable music listening. Kenwood's non-compromise approach to designing has
assured the high power and low distortion which characterizes the most
expensive audio equipment.

Ideal for
listening to the finest stereo records

With the
high quality of modern stereo records, Kenwood engineers gave high priority to
excellent record reproduction. The result is that the KA-1500 reproduces the
RIAA curve that all record manufactures use with accuracy that is absolute to
within ±0,5 dB. In addition, there is the same kind of high overload capacity
that is ordinarily associated with the very finest audio components. This means
no distortion even with high level orchestral climaxes.

Top performance under demanding conditions

Long nonstop
operation, changes in temperature and humidity are factors that can seriously
affect performance. But KA-1500 has special features to perform beautifully at
all times. Advanced, high-efficiency heat sinks, special heat compensation
devices, and massive twin capacitors to stabilize the power supply are only a
few of the many notables.

Facilities
for two tape decks and dubbing

This
advanced feature lets you record simultaneously on two tape decks. It also
allows you to copy from one tape deck onto another.

Hi-Fi
listening at night

The new
loudness control compensates for the loss of fidelity that results at low
volume listening. As a result, you can enjoy all the excitement of stereo with
full fidelity.

Flexible and
accurate tone controls

The
KA-1500's new tone controls allow you to adjust the sound as you like it. You
can increase or decrease the bass and treble independently to match the sound
characteristics of your room and to get the very best out of your speakers.

Extra-large
41 clik stop volume control

The
extra-large volume control knob means you can easily make fine adjustments to
perfectly achieve the perticular level you prefer. The marked positions allow
quick relocation of any previous setting.

Kenwood's
famous "human engineering"

You will
discover that all controls have been carefully placed for easy operation and
designed for positive, instant action. The KA-1500 not only operates and looks
like an excellent audio component, it also "feels" like the
outstanding amplifier that it is.

Specifications

Power Output: 25 watts per channel, min. RMS at 8 Ω, 20 Hz to 20 kHz, with no more than 0,1% THD.

Both
Channel Driven:

29 + 29 watts at 8 Ω (1 kHz)

36 + 36 watts at 4 Ω (1 kHz)

Dynamic Power Output: 100 watts
at 4 Ω

Total Harmonic Distortion: 0.1% at rated power into 8Ω; 0,05% at 1 watt into 8 Ω

Top
performance with a quartz lock system and ideal ease of operation that
complements an abundance of information.

In addition
to its quartz lock system, the RT-2000 has a front-end with a 5-gang dual-gate
MOS FET that guarantees reception sensitivity, and an FM PLL MPX section for
superior stereo separation and a wide dynamic range. This model stands on its
own in performance and quality.

QUARTZ LOCK

As obvious
as it may seem, a tuner's true worth is determined by the accuracy of its
tuning. Both of Rotel's 2000 series tuners ensure absolute precision by using a
quartz crystal oscillator lock system.

Rotel's
quartz lock system automatically compares the precise 10,7 MHz emaneting from
the oscillator with the approximate 10,7 MHz of the intermediate frequency
(IF). Should there be a discrepancy a positive or negative signal is
accordingly emitted by the phase comparator which passes through the low pass
filter (LPF) and serves to lock the local oscillator.

Touching the
tuning knob unlocks the quartz control. Releasing one's hand from the tuning
knob automatically activates the quartz lock circuit which then maintains the
station selected. Once tuned stable reception is quaranteed and drift is
eliminated regardless of changes oscillation is locked.

FM FRONT
END, IF SECTION

Rotel uses a
linear-frequency precision 5 gang variable capacitors. The RT-2000 has a 1
Dual-Gate MOS FET stages, both employing the best low-noise components, with
resultant superior interference reiection capability as well as having a
positive effect on cross modulation interference. The intermediate frequency
band is divided into 2 stages, WIDE and NARROW, which ensures superior sound
quality under varying conditions of reception, and the linear phase filter aids
in low distortion and superior stereo separation.

AM SECTION

The
RT-2000's AM-front -end uses a 16-pin dual-in-line IC package with great
resistance to external interference as well as much improved performance.
Advanced circuitry means AM broadcasts also become a source for high fidelity
sound reproduction.

MULTIPATH
INTERFERENCE SUPPRESSION

The
multipath phenomenon in FM reception, similar to double images on television ,
can adversely affect sound fidelity. With the Multipath switch "ON"
it is possible to select the optimum position for an antenna. The degree of
multipath interference can be checked with the signal meter indicator.

SUPERIOR MPX
SECTION

In order to
improve frequency characteristics in the MPX section, Rotel has paid particular
attention to the cut off of the pilot signal (19 kHz) and weakening of the
carrier signal (38 kHz). By using LC block filters, high frequency range drop
is minimized and a wide range is guaranteed, with the result that rich sound
reproduction is possible. The PLL IC is
employed to assure constant high stereo separation at low distortion for wide
dynamic range.

IF BAND
SELECTOR

IF
(Intermediate Frequency) is the front end output (unified at 10,7 MHz for FM)
resulting from the difference between the broadcasting signal received and the
oscillator frequency. Rotel makes it possible to select between two options
Wide or Narrow. When reception is weak,
use of a narrow IF band can result in superior selection.

DOLBY FM

The RT-2000
incorporates a 25µs de-emphasis switch, in case of a use with an external Dolby
NR adapter.

HI BLEND
SWITCH

Rotel's
Hi-Blend switch creates a faithful and easy-to-listen-to reproduction by
cutting out unwanted high frequencynoise with minimum loss for stereo
separation and frequency response.

The
component that answers the needs of the most discriminating enthusiast.
Essential for maximum flexibility in high fidelity recording and reproduction.

Capable of
improving and expanding original sound components and range. Left and right
channels independent. Increased fidelity possible by operating the 10 resonant
frequency level settings for left and right channels. Class A operation.
Discrete resonant circuitry. Less than 0,005% THD. Equipped for tape recorder
connection.

Here, at
last is a power amplifier output stage that actually adds no distortion to the
music signal. Although the actual techno;ogy involved in the ZDR (Zero
Distortion Rule) amplifier is quite sophisticated, the basic principle of this
incredibile high-accuracy amplifier is quite simple. Essentially the Zero
Distortion Rule system consists of a distortion detector derives a signal
corresponding to any distortion products originating in the amplifier itself,
and the summer adds this signal back into the original audio / distortion
signal - out of phase with the original signal. This effectively cancels the
distortion signal, leaving the audio signal intact and virtually
distortion-free. Of course, this system has no effect on distortion originating
in the source signal, only on distortion generated within the power amplifier
itself. From the above description we can see that if the derived out-of-phase
distortion signal were somehow made larger than the original distortion signal,
summing these signals would actually result in a negative distortion product.
With this ingenious system, it has become possible to produce a power output
stage that actually exhibits no inherent distortion.

Zero
Distortion Rule vs. Negative Feedback

Negative
feedback (NFB) is the most commonly used means for reducing distortion in audio
amplifiers. The amount of distortion reduction, however, is directly controlled
by the amount of feedback applied. This means that in order to reduce
distortion to zero, infinite feedback must be applied. Obviously, it is
physically impossible to create infinite negative feedback, and therefore also
impossible to achieve zero distortion by this method. Increasing application of
negative feedback can only approach the zero distortion ideal, while ZDR
actually permits crossing the zero distortion line and creating negative
distortion, making it theoretically possible to completely eliminate
distortion.

Zero
Distortion Rule vs. Feed Forward

The feed
forward system of distortion reduction attemps to cancel distortion by adding
an inverted distortion signal to the audio signal at the amplifier's output
where signal power levels are high. This means that expensive, hig-power feed
forward circuitry is required, and overall power efficiency is extremely low.
Also, the high-power feed forward amplifier required can actually add unwanted
distortion. Zero Distortion Rule performs its distortion cancellation at
the amplifier's inputs, thereby eliminating the power problem. And since the
ZDR circuit is essentially concerned only with low-lwvel signals, it cannot add
any distortion of its own.

Linear
Transfer Bias and the "X" Amplifer

In
addition to the ZDR system, the M-70 feature Linear Transfer Bias circuitry and
Yamaha's remarkable "X" Power Amplifier system. The Linear
Transfer Bias circuit minimizes the problem of crossover distortion due to
non-uniform linearity between the power transistors in a push-pull power stage.
By applying precisely calibrated bias to each transistor in the M-70's cascoded
push-pull power circuit and thereby staggering the operating point of each a
perfectly linear composite transfer characteristic is achieved, ensuring
negligible crossover distortion levels.

The
"X" Power Amplifier achieves extremely high amplification efficiency
by switching the power supply voltage between two voltage levels - low and high
- according to the size of the signal being processed. For average signal
levels, for example, the lower supply voltage is used, while the high supply
voltage is instantaneously switched in whenever a high-level music peak is
detected. This system eliminates the power wasted in the form of heat that
conventional systems must dissipate with large, finned "heat skins".
The fact that the "X" Power Amplifier permits true high-power music
amplification with maximum efficiency and minimum heat generation means that
the entire amplifier circuit operates under optimum conditions at all times,
ensuring the cleanest most accurate music reproduction. The unbeatable
combination of the Linear Transfer Bias circuit, "X" Power
Amplification, and Zero Distortion Rule amplifier design results in outstanding
low-distortion power performance and incredible power efficiency for unmatched
reproduction precision and exceptionally natural sound quality.

"X"
Power Purity

The concept of "pure power" is extremely important in
achieving the highhest power amplifier performance. That is, the power source
that supplies power to the actual power amplification circuitry must be capable
of providing extremely stable power and at the same time supply as much power
as the amplifier circuitry demends without "running out".
The Yamaha "X" power supply easily meets the above
requirements, with greater efficiency and power capacity than any other power
system of its size or weight. In principle, the "X" power supply
controls the amount of power fed from the AC line to the power supply to
precisely match the amount of power supply to precisely match the amount of
power consumed by the amplifier requires only a small amount of power for
average music levels, or a large amount for high-level music peaks, the
"X" power supply feeds precisely the required amount of power to the
amplifier circuitry. Naturally, this means that all the supplied power is
consumed, achieving remarkable power efficiency. In terms of stability, the
"X" power supply affords exceptionally high regulation capabilities.
Line supply voltage variations of as much as ±10% have no effect on the "X" power supply's output
voltage, and resistance to influence by load variations is similarly high. The
"X" power supply system permits the amplifier circuitry to operate at
optimum efficiency under optimum conditions at all times, ensuring that the
music source is reproduced with maximum accuracy.

Speaker
Level Controls

In
addition to speaker A/B selectors that permit one-touch selection of two sets
of stereo speakers, the M-70 features independent level controls for the left
and right speakers in two stereo pairs. That is, you have independent left and
right speaker level controls for speaker pair "A", and left and right
level controls for speaker pair "B". These controls let you
independently set the maximum power level that will be sent to the respective
pair of speakers, protecting low-power-capacity speakers from excessive power
levels, or matching the output level of two sets of speakers of different
efficiency. Independent control over left and right speaker level lets you
preset the balance of your system for optimum stereo imaging depending on the
positioning of your speakers and the acoustics of your listening room.

20-LED
Peak Power Output Meters

These
bright, attractive power meters let you see at a glance just how much power is
acctually being fed to your speakers. This makes it easier to determine the
proper setting of the speaker level controls to prevent speaker breakup
distortion or burnout due to power levels exceeding the speaker's capacity.
zFor easier reading, these advanced meters feature dual switchable ranges and s
peak hold function that displays the highset encountered power levels for
considerably longer than the overall meter fall time.